<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>浮动 和清除浮动</title>
    <style>
        #one{
            border:4px solid  blue;
            width:30px;
            height: 50px;
            float: right;
        }
        #jj{
            clear: right;
        }
        #two{
            border:4px solid  black;
            width:30px;
            height: 50px;
        }
        #tree{
            border:4px solid  yellow;
            width:30px;
            height: 50px;
        }
        #four{
            border:4px solid red;
            width:30px;
            height: 50px;
        }
    </style>
</head>
<body>
<div id="one">

</div>
<div id="jj">

</div>
<div id="two">

</div>
<div id="tree">

</div>
<div id="four">

</div>
<div id="a">

</div>

</body>
</html>